eurban
Well-Known Member
"it does sweet F.A . . ."
?????????????
?????????????
Gen 2 exup for noise or power gain?
- Thread starter JRO
- Start date
ballmead
Wizard
F#@k All
Sent from my Nexus 5 using Tapatalk
Sent from my Nexus 5 using Tapatalk
RKS
Member
Sharing my personal experience with the exup valve is climbing out on a limb should I wait till post 257 to do that?
Dustin
Moderator
Don't fret, it's just that this subject has been beaten to death.
Welcome to the forum!Certainly the EXUP is functional for power on many other Yamaha bikes, just not this one in particular.
eurban
Well-Known Member
You said "For those who think exup valves are for noise only WRONG"
This is your first post
Thread is OLD and on a subject that has been gone over and over and over and over again
Your statement is confrontational and suggest that peoples understanding of the the EXUP is "WRONG" . . .
In general, your statements indicate that you either didn't read or didn't understand this thread or other threads on the subject because no one is making any sort of broad generalizations about Yamaha's EXUP valve in all applications or the concept of an exhaust power valve in general. Most of us are quite familiar with the EXUPs benefits in the GenI FZ1 and its use by Yamaha (and other manufacturers; they will call it something else) in many of their bikes.
All this doesn't change its power increasing function (or lack there of) in the GenII
Basically, its wasn't really worth waking up a old tired / dead thread to tell people that they are wrong about things that they never thought in the first place.
Last edited:
Lonney
Wizard
Do you have to adjust this exup valve at 26,000 miles too ?
RKS
Member
Gen 2 exup for "noise" or power gain . I'm trying to answer this question . The exup on the gen2 is for power ,when the valve moves even slightly it changes the way the pipe sounds , there are few here that understand how the valve works , there are no huge gains from the gen2 exup just slightly more tourque at lower revs or a sweeter running engine personally I would reattach the cables on the stock can, not trying to cause a shit fight here sorry if I offend the sensitive posters.
Dustin
Moderator
My understanding is that the EXUP on the Gen 2 FZ1 actually starts to close at 6000 RPM to meet noise regulation laws. The default position is fully open and remains that way at most of the RPM range and in most operating conditions. Some of the FZ1 wizards such as Ivan have tested and confirmed that the EXUP does not give any discernible power advantage
Yamaha's factory GYTR slip-on also eliminates EXUP and Yamaha claims more power and torque, even below 6000 RPM.
Yamaha's factory GYTR slip-on also eliminates EXUP and Yamaha claims more power and torque, even below 6000 RPM.
eurban
Well-Known Member
You really should read up on both this site and (even more so) the FZ10a site on performance subjects for the GenII. You say earlier that Yamaha (on the genII) did a pretty good job on torque / yours pulls nicely for 2k on up. . .While the GenII may pull cleanly from low revs it is actually in a severely castrated state of tune as it comes from the factory. Your stock exhaust has two catalytic convertors clogging things up as well as collector pipe that in order to fit the two cats is too short to make proper power in the midrange. There is also power robbing programming for the secondary throttle plates and timing based power restrictions in 1st 2nd and 3rd gears. There is also snatchy throttle issues that mostly can be traced back to programmed in fuel cut on decleration. Basically Yamaha severely corked up the GenII and it responds amazingly well to exhaust and intake mods as well ecu reprogramming combined with fueling mods (Power Commander). Bike is transformed in both power level and the quality in the way in which power is delivered. Full package bike is making about 100 hp at 7k which is about 25hp more than the stock bike at that RPM. That is a huge miderange difference that you can feel every ride and the power delivery is wonderfully smooth. Top end is now around 150hp, up close to 30 from stock. Basically, decastrated, the GenII makes similar power to the R1 of its era
Calling the GenII's exhaust valve "EXUP" is really a marketing move by Yamaha. It really does nothing for the torque that you are imagining that it does. Its default state is fully open and it slightly closes for only a very brief moment during acceleration from 5-6k rpm ball park (where noise regs are tested). It does absolutely nothing for your low end torque. Here's a youtube video that you can watch and see the valve in action. https://www.youtube.com/watch?v=UGA3kaBHzVc
If you are interested you can also read this old thread from the FZ10a site:
EXUP - Torque Related, Noise Reduction or Both - FZ1OA Message Board
Like I have said before, this subject has really been beaten to death, and for nearly as long as the GenII has been around (8+years) You might want to join the FZ10a site as it is a bit more technically oriented. . .If you post, you might want to start with a question though
Last edited:
RKS
Member
Thanks for all that information I have watched that on you tube before notice how the valve starts moving at around 4k and tends to vary somewhat I still think its main use it help with dip in power/torque at certain revs and load just my opinion right or wrong. Most of the 25 bikes I've had over the year's have been badly restricted from new first thing I would do is cut open the stock exhaust remove most of restrictive rubbish weld it back up only to find in most cases it actually went worse, then I would go convince my wife my new toy was useless without more $$ - new exhaust and k@n and jet kit, common story I know . The gen2 has had a few issues since its release mostly the fuel cut throttle snatch and fuel mapping etc as time has gone on they improved , the 2010 is dam near perfect from 2k to 12k I could imagine the awesome bike you guys have after the mods with extra 20 or 30 hp I will probably do the same when I get bored with it, as for now I happy with it stock and riding around in the wee hours due to work wont offend the locals. Sorry to get off track jro I would reattach the cables if your happy with it stock what have you got to loose otherwise its like walking around with a shoe lace undoneYou really should read up on both this site and (even more so) the FZ10a site on performance subjects for the GenII. You say earlier that Yamaha (on the genII) did a pretty good job on torque / yours pulls nicely for 2k on up. . .While the GenII may pull cleanly from low revs it is actually in a severely castrated state of tune as it comes from the factory. Your stock exhaust has two catalytic convertors clogging things up as well as collector pipe that in order to fit the two cats is too short to make proper power in the midrange. There is also power robbing programming for the secondary throttle plates and timing based power restrictions in 1st 2nd and 3rd gears. There is also snatchy throttle issues that mostly can be traced back to programmed in fuel cut on decleration. Basically Yamaha severely corked up the GenII and it responds amazingly well to exhaust and intake mods as well ecu reprogramming combined with fueling mods (Power Commander). Bike is transformed in both power level and the quality in the way in which power is delivered. Full package bike is making about 100 hp at 7k which is about 25hp more than the stock bike at that RPM. That is a huge miderange difference that you can feel every ride and the power delivery is wonderfully smooth. Top end is now around 150hp, up close to 30 from stock. Basically, decastrated, the GenII makes similar power to the R1 of its era
Calling the GenII's exhaust valve "EXUP" is really a marketing move by Yamaha. It really does nothing for the torque that you are imagining that it does. Its default state is fully open and it slightly closes for only a very brief moment during acceleration from 5-6k rpm ball park (where noise regs are tested). It does absolutely nothing for your low end torque. Here's a youtube video that you can watch and see the valve in action. https://www.youtube.com/watch?v=UGA3kaBHzVc
If you are interested you can also read this old thread from the FZ10a site:
EXUP - Torque Related, Noise Reduction or Both - FZ1OA Message Board
Like I have said before, this subject has really been beaten to death, and for nearly as long as the GenII has been around (8+years) You might want to join the FZ10a site as it is a bit more technically oriented. . .If you post, you might want to start with a question though
eurban
Well-Known Member
Just one more thing here and I'll leave it alone. Here's a dyno chart (2nd chart) from Ivan comparing the stock bike's power output to a heavily modded one. I don't think the modded bike has a full exhaust system on it and it is definitely not his latest "full package" which includes the ECU flash . . .
Note the dip in the stock bike's torque curve right around 4.5K. This is followed by a very slight bump at around 5.3K. Depending on when the EXUP's tiny window of opperation occurs (I actually see it as being later in RPM range than you do) you could make an argument to it either hurting power / creating a small dip or helping power creating a slight boost. Of course the modded bike has a similar dip in this area so it may well be more a function of the stock (compromise design) header. In general, one would typically expect any useful restriction of exhaust flow to be earlier that even 4k in the RPM range but I suppose anything is possible. The FACT that it operates in such a small window (that is suspiciously similar to the RPM ranges where sound testing is done) and the demonstrated usefullness (read Bike magazine's Mike Armitages history of EXUP piece) it can have in suppressing noise, there is a very strong case to made to call the GenII's EXUP as primarily a noise limiting device.
PS: Looked at the Youtube video again and I agree that the EXUP seems to be operating primarily in the 4-5K rpm window.
PPS: Just added a Ivan dyno chart (first chart) comparing "full package" power outputs with and without the benefits of ECU flashing. The flashed ECU is the blue line. Compare this to the stock dyno chart and you can see just how neutered the stock machine is . . .
Note the dip in the stock bike's torque curve right around 4.5K. This is followed by a very slight bump at around 5.3K. Depending on when the EXUP's tiny window of opperation occurs (I actually see it as being later in RPM range than you do) you could make an argument to it either hurting power / creating a small dip or helping power creating a slight boost. Of course the modded bike has a similar dip in this area so it may well be more a function of the stock (compromise design) header. In general, one would typically expect any useful restriction of exhaust flow to be earlier that even 4k in the RPM range but I suppose anything is possible. The FACT that it operates in such a small window (that is suspiciously similar to the RPM ranges where sound testing is done) and the demonstrated usefullness (read Bike magazine's Mike Armitages history of EXUP piece) it can have in suppressing noise, there is a very strong case to made to call the GenII's EXUP as primarily a noise limiting device.
PS: Looked at the Youtube video again and I agree that the EXUP seems to be operating primarily in the 4-5K rpm window.
PPS: Just added a Ivan dyno chart (first chart) comparing "full package" power outputs with and without the benefits of ECU flashing. The flashed ECU is the blue line. Compare this to the stock dyno chart and you can see just how neutered the stock machine is . . .
Attachments
Last edited: